reporter: officer rachel meade is patrolling the halls in the gratin school district and students have noticed. >> first couple of days they are like why are you here? because it was new. reporter: since school started this year, she's a constant presence as they respond to a new vocabulary active shooter. >> you want to give power to the people in the classroom. reporter: tragic mass shootings from columbine to sandy hook to last week in oregon have schools rethinking how they will respond to an armed intruder. it's a departure from the radiational school lock down which is keeping the kids in the classroom and simply locking the door. >> we've really taught our kids it's okay to evacuate run and hide in the woods and things like that. so, if god forbid something happens they would know what to do. reporter: there's better marking of locations and the school. should running become an option. this video shows how drills have been carried out at other school districts under a program called alice. alert lock down inform counter evacuate. >> it's not just sitting there and waiting it's r